| 1. |
- Kraft, Petr, et al.
(författare)
-
Uniquely preserved gut contents illuminate trilobite palaeophysiology
- 2023
-
Ingår i: Nature. - : Springer Nature. - 0028-0836 .- 1476-4687. ; 622:7983, s. 545-551
-
Tidskriftsartikel (refereegranskat)abstract
- Trilobites are among the most iconic of fossils and formed a prominent component of marine ecosystems during most of their 270-million-year-long history from the early Cambrian period to the end Permian period1. More than 20,000 species have been described to date, with presumed lifestyles ranging from infaunal burrowing to a planktonic life in the water column2. Inferred trophic roles range from detritivores to predators, but all are based on indirect evidence such as body and gut morphology, modes of preservation and attributed feeding traces; no trilobite specimen with internal gut contents has been described3,4. Here we present the complete and fully itemized gut contents of an Ordovician trilobite, Bohemolichas incola, preserved three-dimensionally in a siliceous nodule and visualized by synchrotron microtomography. The tightly packed, almost continuous gut fill comprises partly fragmented calcareous shells indicating high feeding intensity. The lack of dissolution of the shells implies a neutral or alkaline environment along the entire length of the intestine supporting digestive enzymes comparable to those in modern crustaceans or chelicerates. Scavengers burrowing into the trilobite carcase targeted soft tissues below the glabella but avoided the gut, suggesting noxious conditions and possibly ongoing enzymatic activity.
|
|
| 2. |
- Laibl, Lukas, et al.
(författare)
-
The ontogeny of Ellipsocephalus (Trilobita) and systematic position of Ellipsocephalidae
- 2015
-
Ingår i: Alcheringa. - : Informa UK Limited. - 0311-5518. ; 39:4, s. 477-487
-
Tidskriftsartikel (refereegranskat)abstract
- Laibl, L., Fatka, O., Budil, P., Ahlberg, P., Szabad, M., Voka, V. & Kozak, V., 24.3.2015. The ontogeny of Ellipsocephalus (Trilobita) and systematic position of Ellipsocephalidae. Alcheringa 39, 477-487. ISSN 0311-5518.Well-preserved early holaspid stages of the Cambrian Series 3 trilobites Ellipsocephalus hoffi (Schlotheim, 1823) and Ellipsocephalus polytomus Linnarsson, 1877 have been discovered in the Pibram-Jince Basin (Czech Republic) and Jamtland (Sweden), respectively. Both species show remarkable morphological changes during late ontogeny. The earliest holaspides share long genal spines, and long macrospines on the second thoracic segment. Whereas macrospines disappear abruptly in later stages, genal spines are progressively shortened. Consequently, the ontogeny of trilobites of Ellipsocephalidae is revised. The morphology of early meraspid cranidia and ontogenetic patterns in the disappearance of macrospines suggest that this family is closely related to members of Redlichiida rather than Ptychopariida.
|
|
